401 research outputs found
Implementation of packaged integrated antenna with embedded front end for Bluetooth applications
The design, integration and realization of system in enhanced package approach towards fully functional system level integration by using a compact Bluetooth USB dongle as the demonstrator is presented here. The integration was done on FR4 substrates, which is totally compatible with today’s printed circuit board manufacturing capability. A commercially available Bluetooth integrated chip was chosen as the chipset of our demonstrator, and a package integrated antenna together with an embedded front end completes the system in package integration. The front end developed here is based on an embedded meander line combline filter and an embedded transformer balun. The filter has a 35% area reduction when compared with the classical combline filter and similar performance. The balun has the coils distributed on three layers that minimized the board area needed it and optimizes the performances. The proposed packaged integrated antenna approach is successfully demonstrated here and the new module shows excellent performance when compared with a commercial solution, surpassing the normal Bluetooth class II dongle range which is up to 10 m and increasing the module range up to 120 m without an extra power amplifier
Carrier dynamics and infrared-active phonons in c-axis oriented RuSrGdCuO film
The conductivity spectra of c-axis oriented thin RuSrGdCuO film
on SrTiO substrate, prepared by pulsed-laser deposition, are obtained from
the analysis of the reflectivity spectra over broad frequency range and
temperatures between 10 and 300 K. The free charge carriers are found to be
strongly overdamped with their scattering rate (1.0 eV at room temperature)
exceeding the plasma frequency (0.55 eV). Four phonon lines are identified in
the experimental spectra and assigned to the specific oxygen related in-plane
polarized vibrations based on the comparison with the results of a lattice
dynamics shell model calculations.Comment: 3 pages, 4 figure
Nanostructured metal-fullerene field emission cathode
One of the important properties of carbon nanostructures is their cold electron
emission ability. Carbon nanotubes and other nanostructures are capable of
emitting high currents at relatively low electrical fields. They are already
used in functional devices such as field emitters. The conventional method of
carbon nanostructured cathodes manufacturing is thin film nanocarbon deposition
using CVD process on electrically conducting substrate like metal or doped
silicon plates. The alternative way of manufacturing of carbon field emission
cathodes is based on a special processing of carbon microfibers or composite materials in metal holders. We used the similar approach to produce composite
metal-nanocarbon material which may be easily processed and shaped to
produce an effective field emission cathode which can be easily fixed an any
environment.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2058
Экспресс-определение содержания цинка и железа в волосах человека методом рентгенофлуоресцентного анализа
There are deseases («microelementoses») determined by deficiency or abundance of essential elements in human body. Human hair is biological substratum that can reflect organism processes connected with essential micro- and macroelements. The results present the dependences on gender and oncodesease. The authors worked out the method of X-ray-fluoremetry analysis without mineralization of biomaterial.Известен ряд заболеваний (микроэлементозы), вызываемых недостатком или избытком необходимых для организма элементов. Волосы являются биологическим субстратом, отражающим процессы в организме с участием микро- и макроэлементов. В работе представлены результаты определения цинка и железа в волосах человека в зависимости от пола и наличия онкозаболевания. Для исследования авторами разработана экспресс-методика рентгенофлуоресцентного анализа, не требующая предварительной пробоподготовки анализируемого биосубстрата. Валидационные характеристики доказаны с помощью атомно-абсорбционной спектрометрии как референтного метода
Two-particle pairing and phase separation in a two-dimensional Bose-gas with one or two sorts of bosons
We present a phase diagram for a dilute two-dimensional Bose-gas on a
lattice. For one sort of boson we consider a realistic case of the van der
Waals interaction between particles with a strong hard-core repulsion and a
van der Waals attractive tail . For , being a hopping
amplitude, the phase diagram of the system contains regions of the usual
one-particle Bose-Einstein condensation (BEC). However for we have total
phase separation on a Mott-Hubbard Bose solid and a dilute Bose gas. For two
sorts of structureless bosons described by the two band Hubbard model an s-wave
pairing of the two bosons of different sort is possible.
The results we obtained should be important for different Bose systems,
including submonolayers of He, excitons in semiconductors, Schwinger bosons
in magnetic systems and holons in HTSC. In the HTSC case a possibility of
two-holon pairing in the slave-bosons theories of superconductivity can restore
a required charge of a Cooper pair.Comment: 10 pages, 2 figure
Fermionic SK-models with Hubbard interaction: Magnetism and electronic structure
Models with range-free frustrated Ising spin- and Hubbard interaction are
treated exactly by means of the discrete time slicing method. Critical and
tricritical points, correlations, and the fermion propagator, are derived as a
function of temperature T, chemical potential \mu, Hubbard coupling U, and spin
glass energy J. The phase diagram is obtained. Replica symmetry breaking
(RSB)-effects are evaluated up to four-step order (4RSB). The use of exact
relations together with the 4RSB-solutions allow to model exact solutions by
interpolation. For T=0, our numerical results provide strong evidence that the
exact density of states in the spin glass pseudogap regime obeys \rho(E)=const
|E-E_F| for energies close to the Fermi level. Rapid convergence of \rho'(E_F)
under increasing order of RSB is observed. The leading term resembles the
Efros-Shklovskii Coulomb pseudogap of localized disordered fermionic systems in
2D. Beyond half filling we obtain a quadratic dependence of the fermion filling
factor on the chemical potential. We find a half filling transition between a
phase for U>\mu, where the Fermi level lies inside the Hubbard gap, into a
phase where \mu(>U) is located at the center of the upper spin glass pseudogap
(SG-gap). For \mu>U the Hubbard gap combines with the lower one of two SG-gaps
(phase I), while for \mu<U it joins the sole SG-gap of the half-filling regime
(phase II). We predict scaling behaviour at the continuous half filling
transition. Implications of the half-filling transition between the deeper
insulating phase II and phase I for delocalization due to hopping processes in
itinerant model extensions are discussed and metal-insulator transition
scenarios described.Comment: 29 pages, 26 Figures, 4 jpeg- and 3 gif-Fig-files include
Measurement of (1020) meson leptonic width with CMD-2 detector at VEPP-2M Collider
The (1020) meson leptonic width has been determined from the combined
analysis of 4 major decay modes of the resonance () studied with the CMD-2 detector at
the VEPP-2M collider. The following value has been obtained:
keV.
The meson parameters in four main decay channels have been also
recalculated: , , , .Comment: 14 pages, 3 figure
Study of the process e+e- to pi+pi-pi+pi-pi0 with CMD-2 detector
The process e+e- to pi+ pi- pi+ pi- pi0 has been studied in the center of
mass energy range 1280 -- 1380 MeV using 3.0 1/pb of data collected with the
CMD-2 detector in Novosibirsk. Analysis shows that the cross section of the
five pion production is dominated by the contributions of the eta pi+pi- and
omega pi+pi- intermediate states.Comment: 8 pages, 3 figure. Submitted to Phys. Lett.
Study of the Process in the C.M.Energy Range 1.05-1.38 GeV with CMD-2
The process has been studied with the CMD-2 detector
using about 950 events detected in the center-of-mass energy range from 1.05 to
1.38 GeV. The cross section exceeds the expectation based on the contributions
of the rho(770), omega(782) and phi(1020) mesons only.Comment: 12 pages, 3 figures, uses elsart.cls, submitted to Physics Letters
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